The present invention relates to a technique for detecting foreign material on the surface of plasma processing apparatus, i.e., for detecting foreign material accumulated on the surface of the processing chamber of the plasma processing apparatus.
The surface of various parts used in the vacuum processing chamber of the plasma processing apparatus is processed by the anode oxidization method such as metal oxide or ceramics, alumite processing or polishing processing. However, according to the washing state after the processing, the washing state after the wet cleaning, or the change of the surface state by the plasma processing, minute foreign material (particles) may be emitted into the processing chamber during operation of the device. The foreign material adheres to the surface of the sample to be processed, causing processing defect of a semiconductor device as a product and lowering the yield or the device operation efficiency.
For this, for example, when reassembling the vacuum processing chamber after the wet cleaning, it is necessary to accurately manage the amount of the foreign material adhering to surface of the respective parts constituting the vacuum processing chamber.
As a device for measuring the foreign material, JP-A-2000-321180 discloses a surface contamination measuring device including suction means for sucking in the air from the vicinity of the measuring object, a measuring unit for measuring the amount and component of the particles in the sucked air, and discharge means for discharging a fluid to the surface of the measuring object. Moreover, this measuring device includes a shielding member formed by a flexible member around the sampling member forming an air suction hole and discharge hole, thereby effectively catching particles.
Moreover, JP-A-7-103863 discloses a device including a spray nozzle for spraying gas to the surface of the measurement object parts, a catch suction tube for collecting the gas sprayed to the surface of the parts via the spray nozzle, and inspection means such as a dust counter for inspecting the adhering material contained in the gas sent into the catch suction tube.